(1) Field of the Invention
The present invention relates to corrosion-resistant members to be exposed to a chlorine gas-based atmosphere at not less than 600.degree. C.
(2) Related Art Statement
In the current film-forming processes such as the hot CVD (chemical vapor deposition), the plasma CVD and sputtering for semiconductor wafers, a heater is necessary for heating such a semiconductor wafer. NGK Insulators, Ltd. proposed aluminum nitride sintered bodies having high corrosion resistance against the halogen-based corrosive gas as substrates for heaters. Particularly, it is known that the dense aluminum nitride sintered body is a highly heat-conductive material, and its volume resistivity is not less than 10.sup.8 .OMEGA.-cm. Therefore, the dense aluminum nitride sintered body is advantageous as a substrate in the heater for producing the semiconductors.
NGK Insulators, Ltd. repeatedly and variously investigated materials for producing the semiconductors, and proposed substrates which have heat resistance, heat impact resistance and corrosion resistance against halogen-based corrosive gas particularly improved by surface-coating a sintered body of aluminum nitride with a dense film of silicon carbide.
However, a heater has not been known yet, which could heat semiconductors up to not less than 600.degree. C. without causing contamination thereof under the condition that the heater is exposed particularly to the chlorine based corrosive gas. Further, a heater has not been known yet either, which would not cause peeling or degradation of a corrosion-resistive film even after being exposed to the chlorine-based corrosive gas at a high temperature range of not less than 600.degree. C. upon application of heat cycles to the heater between a low temperature and such a high temperature range.